Joseph may have used his seer stone to view the location of the plates after Moroni told him where they were

There is considerable evidence that the location of the plates and Nephite interpreters (Urim and Thummim) were revealed to Joseph via his second, white seer stone. In 1859, Martin Harris recalled that "Joseph had a stone which was dug from the well of Mason Chase...It was by means of this stone he first discovered the plates."[1]

Some critics have sought to create a contradiction here, since Joseph's history reported that Moroni revealed the plates to him (JS-H 1:34-35,42). This is an example of a false dichotomy: Moroni could easily have told Joseph about the plates and interpreters. The vision to Joseph may well have then come through the seer stone, as some of the sections of the Doctrine and Covenants (e.g., Section X) would later be revealed. One account matches this theory well:

I had a conversation with [Joseph], and asked him where he found them [the plates] and how he come to know where they were. he said he had a revelation from God that told him they were hid in a certain hill and he looked in his [seer] stone and saw them in the place of deposit."[2]

Joseph was initially more excited about the Nephite interpreters than the gold plates

Joseph Knight recalled that Joseph was more excited about the Nephite interpreters than the gold plates:

After breakfast Joseph called me into the other room, set his foot on the bed, and leaned his head on his hand and said, "Well I am disappointed."

"Well, I said, "I am sorry."

"Well, he said, "I am greatly disappointed. It is ten times better than I expected."

Then he went on to tell the length and width and thickness of the plates and, said he, they appear to be gold. But, he seemed to think more of the glasses or the Urim and Thummim than he did of the plate for, said he, "I can see anything. They are marvelous."[3]

Martin Harris described the Nephite interpreters

Martin Harris later described the Nephite interpreters as "about two inches in diameter, perfectly round, and about five-eighths of an inch thick at the centre.... They were joined by a round bar of silver, about three-eights of an inch in diameter, and about four inches long, which with the two stones, would make eight inches."[4]

Joseph often used the seer stone to translate

Despite having the Nephite interpreters, Joseph Smith often used the seer stone to translate. This led to an episode in which Martin tested the veracity of Joseph's claim to use the second, white stone to translate:[5]

Once Martin found a rock closely resembling the seerstone Joseph sometimes used in place of the interpreters and substituted it without the Prophet’s knowledge. When the translation resumed, Joseph paused for a long time and then exclaimed, “Martin, what is the matter, all is as dark as Egypt.” Martin then confessed that he wished to “stop the mouths of fools” who told him that the Prophet memorized sentences and merely repeated them.[6]

Joseph used his white seer stone sometimes "for convenience" during the translation of the 116 pages with Martin Harris; later witnesses reported him using his brown seer stone.

Joseph sometimes used the Nephite interpreters in the same manner as his seer stones, even when he was not translating

Mark-Ashurst McGee notes that Joseph used the Nephite interpreters in the same manner as his seer stone, even when he was not translating the plates, and may have removed them from the frame which held them:

On one occasion, while Joseph was digging a well for a woman in Macedon, his wife Emma felt that the plates were in danger and came to tell Joseph. Lucy wrote that Joseph, "having just looked into them before Emma go there[,] he perceived her coming and cmae up out of the well and met her..." [7] It seems doubtful that Joseph would have the eight-inch long pair of glasses with him while at work in the well. It seems that Joseph eventually detached the lenses from their frame and carried them in a pouch as he had his brown seer stone.[8]

↑Joseph Knight, cited in Leonard J. Arrington and Davis Bitton, Saints Without Halos: The Human Side of Mormon History (Salt Lake City, Signature Books, 1981), 6. Spelling and punctuation have been modernized. The original text reads: "After Brackfist Joseph Cald me in to the other Room and he sit his foot on the Bed and leaned his head on his hand and says, well I am Dissopented. Well, say I, I am sorrey. Well, says he, I am grateley Dissopnted. It is ten times Better then I expected. Then he went on to tell the length and width and thickness of the plates and, said he, they appear to be gold. But he seamed to think more of the glasses or the urim and thummim than he Did of the plates for says he, I can see anything. They are Marvelous."